1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method, and an image processing program that process image data including characters.
2. Description of the Related Art
Recently, with a trend of so-called “barrier-free” and “universal design”, it has become important to create documents that can be easily understood by elderly persons, visually impaired persons, and persons having defective color perception. Particularly, the importance of improving the visibility of characters by designing an area of characters and an area other than characters, that is, by designing a combination of background colors, is recognized. Furthermore, designing of colors in drawings and graphs has also been considered as an important issue. For example, a method of printing clearer maps by correcting color designing and the thickness of characters is disclosed (for example, see Japanese Utility Model Registration No. 3101105). Thus, in document creation, it is expected to perform color designing from a barrier-free viewpoint.
Imaging devices in which various types of color correction with respect to a scanned image are incorporated have been known. These devices intend to improve contrast and tone in printing on paper and screen display, while maintaining the original hue (for example, see Japanese Patent Application Laid-open Nos. 2004-252866 and 2001-216498).
However, in the case of a document in which arrangement of colors in a created document itself or the configuration thereof is not appropriate, its readability cannot be improved even by improving contrast and tone. Particularly, there are many documents, which are not easy to read for visually impaired or handicapped persons, since these documents are not created from a barrier-free viewpoint.